Combined mixer, kneader and presser particularly for food processing

ABSTRACT

A combined mixer, kneader and presser for materials particularly for foods such as pasta comprises a housing having a wide diameter mixing portion, a small diameter pressing portion and an intermediate conical kneading portion connected between the mixing portion and the pressing portion. An inlet for the materials to be treated is connected into the mixing portion and the pressing portion has a free end with a discharge which receives a head carrying a press mold through which the material is directed. A driving motor has a driving transmission connected to the free end of the mixing portion of the housing and a single shaft extends through the housing and is connected to the driving transmission and is rotated thereby. The shaft includes a mixing portion having radially extending arms which rotate in the mixing portion of the housing, a kneading portion with a conical core and a kneading screw and a smaller diamter cylindrical pressing portion with a press screw which rotates in the pressing portion of the housing. The pressing portion advantageously comprises a separate shaft element which is received in the hollow interior of the portion making up the mixing shaft and the kneading portion of the shaft. The housing is formed with a door either at the drive end of the mixing portion or at the opposite end adjacent the intermediate conical kneading portion. The door includes a fixed part which is connected to the drive and a movable hinge part which may be swung outwardly from the fixed part. In the one embodiment the swinging part includes all of the housing parts which may be swung openly from a fixed mounting of the housing adjacent the drive end. In the other embodiment the swingable parts include the conical intermediate portion and the pressing portion of the housing. When the door is swung open the individual housing parts are accessible for cleaning and repair.

United States Patent 1 Manser 1 May 28,1974

[ COMBINED MIXER, KNEADER AND PRESSER PARTICULARLY FOR FOOD PROCESSING[75] lnventor: Josef Manser, Uzwil, Switzerland [73] Assignee: GebruederBuhler AG, Gallen,

Switzerland [22] Filed: Nov. 14, 1972 [21] Appl. No.: 306,204

[30] Foreign Application Priority Data Nov. 18, 1971 Switzerland16837/71 [52] [1.8. CI. 259/6, 100/146 [51] Int. Cl B01f 7/08 [58] Fieldof Search 259/6, 5, 191, 192, 193,

Primary ExaminerRobert W. Jenkins Attorney, Agent, or FirmMcGlew andTuttle [57] ABSTRACT A combined mixer, kneader and presser for materialsparticularly for foods such as pasta'comprises a housing having a widediameter mixing portion, a small diameter pressing portion and anintermediate conical kneading portion connected between the mixingportion and the pressing portion. An inlet for the materials to betreated is connected into the mixing portion and the pressing portionhas a free end with a discharge which receives a head carrying a pressmold through which the material is directed. A driving motor has adriving transmission connected to the free end of the mixing portion ofthe housing and a single shaft extends through the housing and isconnected to the driving transmission and is rotated thereby. The shaftincludes a mixing portion having radially extending arms which rotate inthe mixing portion of the housing, a kneading portion with a conicalcore and a kneading screw and a smaller diamter cylindrical pressingportion with a press screw which rotates in the pressing portion of thehousing. The pressing portion advantageously comprises a separate shaftelement which is received in the hollow interior of the portion makingup the mixing shaft and the kneading portion of the shaft. Thehousing isformed with a door either at the drive end of the mixing portion or atthe opposite end adjacent the intermediate conical kneading portion. Thedoor includes a fixed part which is connected to the drive and a movablehinge part which may be swung outwardly from the fixed part. In the oneembodiment the swinging part includes all of the housing parts which maybe swung openly from a fixed mounting of the housing adjacent the driveend. In the other embodiment the swingable parts include'the conicalintermediate portion and the pressing portion of the housing. When thedoor is swung open the individual housing parts are accessible forcleaning and repair.

19 Claims, 11 Drawing Figures PATENTEBMY28 m4 18131382 sum 1 nr- 5'COMBINED MIXER, KNEADER AND PRESSER PARTICULARLY FOR FOOD PROCESSINGBACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates in general to the construction of two devices for pressing andkneading materials and in particular to a new and useful combined mixer,kneader and presser for materials having a single shaft and with ahousing having a hinge portion permitting easy access to the interiorthereof.

2. Description of the Prior Art In the production of pasta, increasedproduction of snacks and animal foods, such as dog food in cube form,has made it necessary to place the individual ingredients which willform the product in finely dosed quantities into a relatively largetrough where the materials are mixed by means of a rotating mixer. Thelarge trough permits a sufficient stay time and action period for theindividual additives such as water and other components, for example,such as semolina or flour materials. After mixing the product is usuallydirected by an auxiliary screw into a kneading and pressing stage, inwhich the product is also either heated or cooled as required. Forexample, in the production of certain types of food products such assnacks, the hot dough is pressed at high temperature through a moldwhere it expands when it issues and is cut into pieces by knives and fedto the packing station for further treatment. Other similar foodproducts requiregelatinized pellets which after they issue from the moldare expanded after they are first dried.

In the known processes three separate machines are generally required: alarge trough mixer, a kneading device and a pressing device.Particularly when all of these three machine components are equippedwith independent variable speed drives, the necessary equipment forcarrying out most treatments of the foods can be effected. Adisadvantage in the known construction is that the separate componentsrequire a large expenditure of money. It is already known to arrange themixing and kneading stages on a single shaft in the production of bread,for example. With such an arrangement there is thus only one drive forthe main power consumers and there is no need for expensive control andregulating devices. In certain dough presses of this type, a mixingtrough and a kneading screw which extends over the entire length of thehousing are arranged on the same shaft. The raw product is added fromthe top onto the longer portion of the mixer length. The mixing bladesadvance the material to one end of the kneading screw, and this pullsthe product at the same time and delivers it at the opposite end of thefinished dough. The nesting of the mixing and kneading device results ina rather expensive construction. A disadvantage of this construction isthe unfavorable transfer of the mixed material to the kneading screwwhich moves the material in an opposite direction. The product is notfed positively from one stage to the other. Even interruptions in thematerial flow are possible with theknown constructions.

In another embodiment of the type mentioned above for the production ofbaking dough, a mixing, conveying and kneading stage of constantdiameter are arranged in series on a continuous shaft, starting at thematerial inlet. For baking dough much water is added to the flour, andthus a relatively liquid dough is obtained which makes it possible topermit mixing and pressing in a simple manner because there issufficient water for each ground particle. The raw flour is mixed inthis construction by small rotating mixing arms directly under the inletand the material is fed by its inclined position directly to thepressing screw which compresses it and feeds it to the kneading stageproper. For pasta about 27-33 percent of water is added to the semolina.If this construction were used for the production of pasta, the semolinawould no longer be wetted uniformly with water, due to the short time inwhich the semolina stays in the mixer, and particularly the semolinagrain could not readily absorb the water in the short time available.This manifests itself later in the form of small white dots on thefinished product. In addition with the known arrangement there is nopressing stage.

In another bread dough press of this type the raw product is feddirectly into the pressing screw. This screw engages the raw product andmixes and kneads it at the same time. In order to intensify the kneadingprocess various diaphragms are arranged in the kneading unit to narrowthe cross section and to interrupt the screw threads. Behind it isarranged a stage with a wider cross section to homogenize the dough andto aerate it and evacuate it if necessary. The finished dough is movedthrough a lateral pipe for further processing. This device also has atits end an inadequately designed pressing stage, despite its very longconstruc tion, and it cannot be used for the production of pasta andanacks, where the pressure of kg/cm and more must be generatedundercertain circumstances.

In order to obtain a homogeneous end product in the production of pastaand partly also of snacks, the semolina or raw product and not the doughmust be mixed very carefully and homogeneously with additives and itmust be wetted, if necessary. If there are still individual unwettedsemolina lumps in the sough, satisfactory products can still be obtainedby additional kneading and beating of the dough.

Another factor that prevents the general use of the known single shaftpress is that it is very expensive and complicated to keep clean so thatthe operating personnelmust receive special training. Due to theconstant change in eating habits, a food manufacture faces the fact thathe must have a great variety of different methods and molds available asit is customary in other industrial sectors and which are very soonoutdated by new recipes. In addition to the requirements of cleanlinessand sanitary conditions, which are demanded today, there is additionalrequirements that due to the frequency change in products and shapes,the cleaning must be effected on the spot and particularly in a veryshort time by less skilled personnel.

SUMMARY OF THE INVENTION The present invention provides a combinedmixer, kneader and presser for materials particularly for food such aspasta which is capable of operation and disassembly for cleaning inorder to maintain sanitary requirements, and which includes a means formixing the raw product uniformly with additives, maintaining a constantstay period while the materials are being subjected to treatment andwhich includes an arrangement which permits it to be used for carryingout many different types of operations, and for feeding the product tothe kneading or pressing stage after the ingredients are first mixed.The single shaft construction, according to the invention, ischaracterized by an arrangement in which at least one side, preferablythe driving side, of the housing at the widest or greatest dimensionportion of the mixing stage is designed as a door which permits thehousing to be swung as a unit, as a pivotal door connection. In thepreferred arrangement the end portion of the mixing chamber which isopposite to the drive connection is formed by a conical portion housinga kneading screw. With the surprisingly simple means described, it isthus possible to use a single shaft press which is satisfactory bothfrom the technical and the sanitary point of view for materials such aspasta, snacks and other foods for human and animal nutrition. Thesanitary requirements are thus met both for the operation and for thecleaning of the device itself. The construction is such that there areno dead corners where semi-processed foods can get'stuck during theoperation. All parts are easy to disassemble and to clean, and this ismade possible primarily by forming the housing with a portion thereof asa hinged part which is swingable to one side of a stationary part inorder to open the end thereof to permit access to the internal operatingmechanisms and parts. In particular the passage from the mixer, whichgenerates no marked axial pressure at the location where it extends intothe kneading stage having a relatively high pressure is made veryaccessible by forming the hinge at the connecting portion between theseparts in a simple and yet, nevertheless, safe manner. The material flowis steady and the conditions in the following stages remain constant inthe housing construction provided. The mixing chamber is dimensionedsubstantially larger than the kneading and pressing chamber so that itprovides a means for establishing good mixing of the ingredients and asufficient stay period during the mixing operation.

The inventive apparatus advantageously includes means for feeding amaterial such as semolina through a regulable feeding element such as alock or screw. The amount of material in the mixer is kept constant byutilizing a feed supply for dosing proper additional amounts to thematerials in the mixer as necessary, and this makes it possible tomaintain a stay period in the mixer at a constant value.

The preferred construction includes a single shaft having a kneadingportion arranged in the kneading portion of the housing which has a coreof tapering form tapering from the larger diameter mixing portion to thesmaller diameter pressing portion of the housing. An air gap is providedbetween the tapering core of the kneading screw and a surroundinghousing portion in order to increase the kneading effect over that whichcan be effected by a very poor conveyance of a kneading screw.

The apparatus of the invention also advantageously includes a high speedmixer connected in the inlet line to the mixer of the main housing andwhich is of small dimension and which provides operation at very highspeed output. In addition the main housing mixing chamber advantageouslyincludes a connection to a pump such as an evacuation pump forestablishing a vacuum in the housing. This makes it possible to exhausta major portion of the air from the product being treated so that thetendency of the dough to form air inclusions is greatly reduced duringthe operation. Extreme values of absolute pressures, that is a vacuum atthe end of the kneading stage, can be eliminated with such anarrangement. The power consumption is reduced compared to the existingsingle shaft presses. There is also no unnecessary mechanical stress onthe dough by kneading or shearing since the fluid semolina is alreadyevacuated and not the viscous dough. The housing advantageously includesmeans for passing a cooling medium or a heating medium through thehollowed walls thereof which makes the unit usable with a process forthe production such as snacks or animal foods. The housing may be formedwith two housing portions arranged side by side so that two mixingtroughs or chambers are connected together and arranged to advance thematerials through separate kneading stages and pressing stages into acommon collecting trough which feeds them through a discharge press. Theinlet feed connection is advantageously arranged to connect into the twomixing chambers at a central location located therebetween. With theinvention any one of the individual sections may be subdivided into morethan one part which are connected to gether such as by a fixed flangejoint connection or by a hinged connection.

Accordingly it is an object of the invention to provide an improvedcombined mixer, kneader and presser for materials particularly for foodssuch as pasta which comprises a housing having a small diameter pressingsection, a large diameter mixing section and an intermediate diameterkneading section connected between the mixing section and the pressingsection and with a single shaft extending through the housing havingmixing, kneading, and pressing elements arranged thereon located in thevarious housing portions, and wherein the housing has a door formationadjacent at least one end ofthe mixing portion which comprises a hingeconnection including a portion which is fixed in respect to the drivemeans for driving the shaft and a portion which may be swung outwardlyto one side of the fixed portion to facilitate access to the interior ofthe housing for removal and cleaning of the associated parts.

A further object of the invention is to provide a device for treatingmaterials, which is simple in design, rugged in construction andeconomical to manufacture.

For an understanding of the principles of the invention, reference ismade to the following description of typical embodiments thereof asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. 1 is a longitudinal sectional view of a portion of a combinedmixer, kneader and presser for treating materials particularly foodssuch as pasta and which is constructed in accordance with the invention;

FIG. 2 is a section taken along the line IIII of FIG.

FIG. 3 is a partial side elevational view of the door mounting shown inFIG. 2;

FIG. 4 is a section taken along the line IV-IV of FIG. 1;

FIG. 5 is a horizontal sectional view of another embodiment of combinedpresser, mixer and kneader;

FIG. 6 is a section taken along the line VI-VI of FIG. 5;

FIG. 7 is a section taken along the line VIIVII of FIG. 1 but with theinternal parts being removed;

FIG. 8 is a side elevational view of the shaft pressing portion;

FIG. 9 is a side elevational view of the shaft kneading and mixingportion;

FIG. 10 is a partial longitudinal sectional view of a another embodimentof combined mixer, kneader and presser; and

FIG. 11 is a longitudinal sectional view of a presser section of thehousing of another embodiment of the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to thedrawings in particular, the invention embodied therein in FIGS. 1-4 and69 comprise a combined mixer, kneader and presser for materials,particularly for foods such as pasta, which includes a raw materialfeeding conduit 100 which connects into a dosing lock 1 which connectsthrough a conduit 45 leading to a high speed mixer 40 which dischargesthrough a conduit 102 into a feed connection 3' of a main housing orhousing 104 of the combined mixer, kneader and presser.

In accordance with the invention the combined mixer, feeder and presser104 includes a mixing stage portion or mixer portion 4 which has aninterior defining a mixing chamber or trough 3 of uniform relativelylarge interior dimension which connects a one end to an intermediatekneading part or conical part 13. The conical part 13 tapers toward itsouter end and is connected at this outer end to a cylindrical pressurepart or pressing part 14 of uniform interior diameter which is of asmaller diameter than the mixing chamber 3. A single shaft generallydesignated 106 is connected at one end to a drive transmission 7 whichis operated by a drive motor 9 driving through a belt gearing 8. Theshaft 106 extends throughout the housing 104 and it includes a mixingshaft portion 6 having mixing arms 5 which extend radially outwardlytherefrom in the mixing chamber 3. In addition the shaft 6 contains akneading portion 10 which includes a conical core I0 with a spiralkneading screw III" which operates in the conical part 13. The shaft 106also includes an outer portion or pressing screw II which extendsoutwardly from the kneading part 10.

The housing includes a double wall formation or cylindrical hollowjacket 12 which tapers conically at the kneading part 13 and it alsoincludes a hollow wall portion at the cylindrical pressing part 14. Thepressing screw portion 11 advantageously comprises a separate part whichis coupled with a shaft piece 15 as shown in FIG. 8 which extendsthrough the hollow portion of the kneading shaft portion 10 and themixing shaft portion 6 and it is connected through a squared end 16 tothe drive mechanism 7. For this purpose the drivemechanism 7 has a shaftwhich drivingly engages the mixing shaft portion 6 and the mixing shaftportion 6 includes a squared interior recess 18 which is engagable withthe squared end 16 of the extension 15 of the pressing shaft portion 11.The torque therefore is applied through the mixing shaft assembly 106 bythe engagement of the shaft portion 6 with the drive mechanism 7 and theportion 6 in turn drives the extension 15 of the kneading portion 11 byengagement of the squared end 16 and the recess 18.

The press screw portion 11 of the shaft I06 has little play between itand the wall of the press portion 14 of the housing so the screw acts asa bearing for the shaft 106 even though there is no pivot bearingitself. On the driving side a very strong end bearing 19 is provided forthe driving shaft of the transmission 7.

In accordance with a feature of the invention the entire end face of thedrive 7 at the location of its connection to the housing 104, is formedas a hinged door construction comprising a pivotal transverse doormember 20 which is mounted on two fixed hinges 21 and 22. In theposition shown in FIG. I the housing is mounted on the door 26 and it isheld in an axially aligned position by securing bolts 23 located on theopposite side of the door from the hinges 211 and 22. The door whichcarries the housing 104 therefore, is locked in a forced closed manneron the transmission 7. The very great shearing forces which act on themixing arms 5 as well as the kneading and pressing parts 10 and 14 areclosed or carried by bearings 19 of the transmission and by the door 20.The static and dynamic forces of the drive are transmitted to the door20 to the housing 104 through a base 25 to the foundation 26.

As best seen in FIG. 2 access to the mixing chamber 3 may be obtainedthrough a service door 27. The door 27 is solid and has top hinges 28and a bottom safety snap closure 29. The door 27 is pressed airtightonto a packing 30 against the housing close to the drive side. A feedinlet pipe 3' connects to the pipe I02 and in addition there is an inletfitting 31 for liquids or other components which are to be added to themix in the chamber 3.

A press mold 32 is connected to the opposite free end of the cylindricalportion I4 and it is secured in position by a flanged end which isbolted in place by retaining bolts 34 which are engaged against an endface 36 of the cylindrical pressing part 14.

The operation of the single shaft combination mixer, kneader and presseris as follows:

The raw product, for example, semolina is fed into the mixing trough 3through the dosing lock 1. Due to the feeding of the product through thechambers with the lock 1 the mixing trough 3 is sealed from theatmosphere. In practice a dosing screw is arranged ahead of the lock,but in order to feed the material thereto, and in some instances adosing screw is substituted for the lock 1. This latter will depend uponwhether the dosing accuracy must be rigidly maintained or whether thepressure conditions in the mixing trough must be controlled. The rawmaterials, water or other admixtures, are charged into the mixingchamber 3 at the drive end and are moved by kneading arms 5 toward'thekneading portion 13 for engagement by the kneading part 10 of the shaftI06.

A very advantageous feature from the sanitary standpoint is' the directengagement of the mixing material by the shaft kneading part 10 whichhas a large diameter portion so that the engagement is over the greatestpossible circumference and thus, dead corners are eliminated. Becausethe kneading already starts on the relatively large diameter of theinterior of the chamber 3 the kneading stage can be kept short, so thatthere will not be any transition cross sections which are difficult toclean and which hinder the flow. The kneading process in generallyinterfered with by the poor conveyance of the materials and by the manyreturn movements of the materials which were required by the prior artdevices. The construction of the present invention with the taperingknead shaft portion provides a particularly advantageous constructionfor the movement of the material. Care is taken that the depth of thescrew portion 10 is not made too great so there will be no tendency fora thick layer of dough to stick to the core, since this would be harmfulto the uniformity of the quality of the end product. Various designs ofthe core 10' and the screw threads 10" may be obtained in order to varythe free flow cross section as required from one process to the next andto effect either an increasing or decreasing cross section between theshaft portion 10 and the wall portion of the kneading section 13 of thehousing. The inlet crossing to the kneading section is deliberately overdimensioned in order to intensify the kneading process. The dosingdevice 1 may be regulated in order to provide a desired in feed to themixing chamber 3 to permit pasta to be produced. The volumetric dosingelement will never have a 100 percent dosing effect, due to the variablespecific volumes. In many cases it is therefore necessary, in order tocorrect deviations from the desired dosage, to keep the amount of theproduct constant with an additional control device such as a controllever (not shown), which may be arranged in the mixing chamber and byemploying a corresponding back coupling or regulation of the dosingwheel of the dosing lock 1. This ensures 100 percent mean stay period inthe mixer since the discharge of the homogeneous dough with the pressingscrew portion 11 is uniform.

The invention permits the easy maintenance of the sanitary requirementsfor operation. As indicated in FIGS. 1-4 and 7-9 the device may bestopped so that all operation is cut off and the interior parts may becleaned rapidly by opening the cleaning doors 20 or 27. For this purposethe main in feed and the dosing lock 1 are stopped and the main drive 7is run for some time thereafter. Any existing residues can be brought byhand toward the kneading screw 10 by opening the service door 27 whichcan stop the entire plant and be discharged by starting the motor againbriefly. The fastening screws 34 at the end of the pressing part 14 areloosened to permit removal of the head 33. The pressing screw shaft 11together with its extension 15 can be pulled out by a few centimeterswith a simple device similar to a ball bearing extractor by bearing onthe end face 36. The square portion 16 of the shaft extension 15 is thuspulled out from the square portion 17 of the drive 7 and the recessedsquare 18 of the hollow mixing shaft portion 6 of the shaft 106 is alsodisengaged. The drive 7 is disconnected from the shaft 106 thuscompleting the disassembly of all of the shaft portions except the shaftportion 10 and the shaft portion 6, as shown in FIG. 9. Thus all of theparts are separated for rapid cleaning as shown in FIGS. 7, 8 and 9. Theshaft portions 6 and 10 are again united to the shaft portion 11 afterthey have been cleaned and the whole shaft assembly is centered in thehousing by the positioning of the pressing portion 11. The doors 20 and27 are again closed and the retaining head 33 is again attached, so thatthe entire press becomes ready again for another opeational run.

Many products which include a part of the mixed material which hasalready been engaged by the kneading screw portion 10 may be returnedinto the mixing chamber 3 particularly if there is no risk that thepartly kneaded lumps will stick to the mixing arms 5. The low effciencyfor the kneading is thus particularly utilized, since a relatively largeair gap 35 is provided between the kneading screw 10 and thecorresponding conical housing 13.

The excess material is returned to the mixing chamber 3. The kneadingscrew portion 10 enforces an additional material movement and a moreintensive mixing in the mixing chamber 3, since a material flowcomponent is enforced opposite to the normal direction of flow of thematerial which is already mixed from the feeding inlet 3 to the kneadingstage at the kneading portion 13. In certain cases it is desirable thatthe mixing shaft portion 6 operate at a speed which is distinct from thepress shaft portion 11 and in'such cases they may be connected to thedrive 7 so that two different speeds can be provided. In some instancesit is desirable that the mixing material be engaged not by an advancingscrew such as the screw 10" but by a ladle-type blade which is arrangedin the mixing chamber 3 and oriented to direct the material toward thekneading stage.

In some instances it is desirable to have a high speed mixer 40 arrangedto process the material delivered through the inlet and before it entersinto the mixing chamber 3. For this purpose a high speed mixer 40includes a shaft having a plurality of high speed mixing arms 42extending radially and which is rotated by a motor 44 driving through aclutch 43. The conduit 45 provides an inlet into the high speed mixer 40and one connection at least, the connection 46, is provided for a liquidcomponent or other components. The high speed mixer 40 has asubstantially higher speed than the mixing shaft 106. The high speedmixer 40 as well as the mixer housing 104 are sealed from the outside bypackings 47.

Since both the lock drive 2 and the high speed mixer drive 44 have verylow motor outputs there is no great loss if only the shaft 106 isrotated by the main motor 9 and no high speed mixer 40 is employed. inlarge plants, -100hp are readily provided for the mixing, pressing andkneading stage, but high speed mixers and locks require only a fractionof this motor output. The principal energy consumer remains combined ona shaft 106. The mixer housing 4 can effect the various phasesseparately and more intensively than the high speed mixer 40. The highspeed mixer 40 should be such that it will mix water and other additivesin a very short time with the main raw product, which is usually also ina flowing or fluid state. The main mixer within the housing 104 permitsa relatively long stay and action period which varies according to theproduct. The arrangement permits not only the use but the absorption ofliquid into the interior of the semolina grain which is a prerequisitefor the production of pasta of high quality. The speeds of the pressingand mixing shaft portions, are in most cases, relatively in goodagreement. They are practically always low and relatively rarelyabovelOO rpm, for the production of pasta, they are rarely over 50 rpm.The inventive construction permits an easy aeration of the entire mixingthrough an aeration connection 50 which is connected through a conduit51 (which is schematically illustrated) and through a valve 52 to a pump53. Particularly in the case of the manufacturing of pasta, theapplication of a vacuum pump 53 will bring considerable advantages inthe mixing trough chamber 3 so that the air inclusions need not beremoved from the viscous dough but are prevented during the formationbefore they start by evacuation of the chamber. In many cases it is thuspossible to work with a much lower vacuum.

Heating or cooling media may be introduced into the hollow wall parts54, 55 and 56 through connections 58. Particularly for the production ofmodern foods such as snacks or animal foods, hot steam can be injectedadditionally into the mixing trough 3 and/or circulated through thehollow walls of the housing. The mixing, dosing, kneading and thepressing stages can be I heated or cooled separately.

The inventive device is thus capable of a surprisingly large number ofuses without changing the concept of the construction which is of greatvalue for the food processing industry which requires, at the presenttime, 1 many changes in operation due to changes of eating habits.

The embodiment of the invention shown in FIG. 5 is advantageous for theproduction of pasta for long products. The dosing lock 1 and theassociated in feed mechanism including the high speed mixer may beconnected as in the FIG. 1 embodiment to a single centrally locatedinlet located between two mixing chambers or troughs 61 and 62 whichoverlap at the center thereof. The mixing arms are selected so that theycan reach into the other mixing trough from respective oppositedirections to result in an increase in kneading and pressing action. Atthe end of the pressing screw 63 and 64 can be arranged bearings 65.Connecting lines 66 lead into a common distribution head 67 having longpressing molds (not shown). The method of operation of this embodimentis not different from the single shaft press but it has a very greatadvantage in that there is a constant change of mixing material andequalization between the two troughs 61 and 62. Expensive controlmechanisms are thus, not necessary so that the housing of solidconstruction is more than compensated, not the least by the fact that avery stable and safe machine is obtained.

In a single shaft press according to the invention, only one part ofthedrive, for example, a belt pulley, can be flanged directly to the door20, particularly when the food to be produced does not change or onlychanges at very long intervals. Likewise the various methods of heatingor cooling or maintaining a vacuum, etc. can be combined as desired.

In the embodiment of the invention shown in FIG. 10 the housinggenerally designated 110 includes a mixing chamber part 71 and acombined kneading part and pressure part which is hinged thereto at ahinge 72. A shaft 112 includes a mixing part 73 rotatable within themixing chamber part 71 and a pressing part which is secured thereto andwhich will rotate in a conical part 114, when the part 70 is returned toan axially aligned position. The shaft 112 is connected through acoupling 74 with a drive shaft 75. The pressing shaft portion 77 maybedisengaged from the remaining shaft portions by disengaging a squaredend 78 from a corresponding recess or seat 79 defined at the outer wndof 6 the pressing part 80.

In FIG. 11 there is shown a single shaft press which includes acylindrical press part made up of two individual lengths 80 and 82 whichare pivoted together at 81 and which may be clamped in an axiallyaligned position by clamping bolts 87 engaging through flange portions86 and 86'. Each jacket 80 and 82 is provided with an inner cylinderpart 83, 83' and an outer cylinder part 84,84 which define an annularcavity for heat exchange media. Each part is provided with a flange85,85 for fastening the other housing parts of the press mold thereto.

Particularly in the processing of certain snacks, where the total lengthof the kneading and pressing parts and hence the jacket parts as well asthe screw shaft contained therein, is frequently over 2 meters, butgenerally in relation to long press cylinders, there is an enormousadvantage for the production as well as the sanitary operation of suchan arrangement, despite the attached parts. The jacket parts 80 and 82can be provided with different heat exchange media, for example, jacketpart 80 can be heated and jacket part 82 cooled.

During the processing the kneading and the pressing shaft can always beremoved for cleaning to make sure, by visual inspection, that they are,in fact, clean. Same holds true for the jacket parts 80 and 82, sincethe jacket part 82 is simply opened like a door by pivoting it about thevertical hinge, and 81 is shown in FIG. 11. The cleaning and the visualinspection are thus considerably facilitated without heavy and longparts having to be moved by a crane, for example.

A particular advantage is that the jacket part 82 can be removed andreplaced directly by a door type press mold retaining head 33 having thesame connections. The machine, according to the invention, can thus befitted better into an existing assembly of prefabricated parts.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be emdodiedotherwise without departing from such principles.

What is claimed is:

1. A combined mixer, kneader and presser for materials particularly forforming foods such as pasta, comprising a housing having a wide diametermixing portion, a small diameter pressing portion and an intermediatekneading portion connected between said mixing portion and said pressingportion, said mixing portion having an inlet for materials to betreated, said pressing portion having a free end opposite to saidkneading portion with a discharge for the material, drive meansconnected to said housing adjacent said mixing portion of said housing,at least one shaft connected to said drive means and rotated thereby andextending axially through said housing, said shaft having a mixingportion with arm means rotatable in said mixing portion of said housing,a kneading portion rotatable in said kneading portion of said housingand a pressing portion rotatable in said pressing portion of saidhousing, said housing having a door formation adjacent at least one endof said mixing portion thereof comprising a hinge connection including aportion fixed in respect to said drive means and a portion which may beswung outwardly to one side of said fixed portion to facilitate accessto the interior of said housing for removal and cleaning of said shaft.

2. A combined mixer, kneader and presser according to claim 1, whereinsaid shaft kneading portion comprises a conically shaped core having awidened end in said mixing portion of said housing and an inwardlytapered smaller diameter end connected to said shaft pressing portionand a spirally progressing screw formation extending outwardly from thesurface of said core.

3. A combined mixer, kneader and presser according to claim 1, whereinsaid shaft kneading portion is tapered in the direction of movement ofthe material.

4. A combined mixer, kneader and presser according to claim 1, whereinsaid mixing portion of said housing is sealed in respect to the outsideso that it may be maintained at a pressure which is distinct from thesurrounding atmosphere.

5. A combined mixer, kneader and presser according to claim 1, includinga material feed line connected to said inlet, a high speed mixerarranged in said feed line and including a driving motor, and arotatable shaft driven by said motor in said mixer having arm means formixing material therein.

6. A combined mixer, kneader and presser according to claim 1, includinga pump connected to said mixing portion of said housing for regulatingthe pressure within said housing.

7. A combined mixer, kneader and presser according to claim 1, includingmeans associated with said housing for selectively and alternativelyheating and cooling portions of said housing.

8. A combined mixer, kneader and presser according to claim 1, includinga feed line connected into said inlet, a closing lock connected to saidfeed line through which the material is passed including a rotatablevane element therein, and means for rotating said vane to provide aregulated feed to said mixing portion of said housing.

9. A combined mixer, kneader and presser according to claim 1, includinga mounting base for supporting said housing, said fixed portion of saidhousing being secured to said mounting base and including said drivemeans, said drive means comprising a transmission connected to saidshaft and a motor connected to said transmission to drive said shaft.

10. A combined mixer, kneader and presser according to claim 1, whereinsaid kneading portion of said shaft comprises a frustroconical coreportion with an outwardly extending progressing screw thread which isspaced inwardly from the interior wall of said intermediate conicalkneading portion of said housing.

11. A combined mixer, kneader and presser according to claim 10, whereinsaid inlet is connected centrally between said mixing portion and saidadditional mixing portion of said housing and comprises the only feedfor both of said portion.

12. A combined mixer, kneader and presser according to claim 1, whereinthere is said at least one shaft comprises a pair of parallelly arrangedlaterally spaced shafts, said housing including a substantiallyidentical additional mixing chamber portion, intermediate portion andpressing portion arranged in parallel relationship with the mixingchamber portions being interconnected centrally.

13. A combined mixer, kneader and presser according to claim 11, whereinsaid feed opening for said mixing portions for said housing is arrangedcentrally between said mixing portion and said additional mixing portionand extends substantially perpendicular to the axes thereof.

14. A combined mixer, kneader and presser according to claim 1, whereinsaid shaft presser portion comprises a rotatable press screw and anextension within a hollow portion of said kneading portion and saidmixing portion of said shaft, said pressing portion of said shaft havingmeans at the end of said extensive portion for coupling said shaft tosaid drive means.

15. A combined mixer, kneader and presser according to claim 1, whereinsaid pressing portion of said housing comprises at least two separatelongitudinally extending portions which are hinged together and whichmay arranged in longitudinally extending axial alignment or broken apartand pivoted about the hinge portion to open them up.

16. A combined mixer, kneader and presser according to claim 1, whereinsaid housing door formation is located between said mixing portion ofsaid housing and said drive means.

17. A combined mixer, kneader and presser according to claim 1, whereinsaid housing door formation is located between said mixing portion ofsaid housing and said intermediate portion of said housing.

18. A combined mixer, kneader and presser according to claim 1, whereinsaid kneading portion and said mixing portion of said shaft comprise asingle hollow piece, said pressing portion of said shaft comprising apress screw formation rotatable in said housing pressing portion and anextension extending through the hollow portion of said kneading portionand said mixing portion of said shaft and means for coupling said mixingportion and said kneading portion and said pressing portion to saiddrive means.

19. A combined mixer, kneader and presser according to claim 18, whereinsaid coupling means comprises a squared end of said presser shaft, saiddrive means including a recess squared end engagable with said squaredend of said presser shaft.

1. A combined mixer, kneader and presser for materials particularly forforming foods such as pasta, comprising a housing having a wide diametermixing portion, a small diameter pressing portion and an intermediatekneading portion connected between said mixing portion and said pressingportion, said mixing portion having an inlet for materials to betreated, said pressing portion having a free end opposite to saidkneading portion with a discharge for the material, drive meansconnected to said housing adjacent said mixing portion of said housing,at least one shaft connected to said drive means and rotated thereby andextending axially through said housing, said shaft having a mixingportion with arm means rotatable in said mixing portion of said housing,a kneading portion rotatable in said kneading portion of said housingand a pressing portion rotatable in said pressing portion of saidhousing, said housing having a door formation adjacent at least one endof saiD mixing portion thereof comprising a hinge connection including aportion fixed in respect to said drive means and a portion which may beswung outwardly to one side of said fixed portion to facilitate accessto the interior of said housing for removal and cleaning of said shaft.2. A combined mixer, kneader and presser according to claim 1, whereinsaid shaft kneading portion comprises a conically shaped core having awidened end in said mixing portion of said housing and an inwardlytapered smaller diameter end connected to said shaft pressing portionand a spirally progressing screw formation extending outwardly from thesurface of said core.
 3. A combined mixer, kneader and presser accordingto claim 1, wherein said shaft kneading portion is tapered in thedirection of movement of the material.
 4. A combined mixer, kneader andpresser according to claim 1, wherein said mixing portion of saidhousing is sealed in respect to the outside so that it may be maintainedat a pressure which is distinct from the surrounding atmosphere.
 5. Acombined mixer, kneader and presser according to claim 1, including amaterial feed line connected to said inlet, a high speed mixer arrangedin said feed line and including a driving motor, and a rotatable shaftdriven by said motor in said mixer having arm means for mixing materialtherein.
 6. A combined mixer, kneader and presser according to claim 1,including a pump connected to said mixing portion of said housing forregulating the pressure within said housing.
 7. A combined mixer,kneader and presser according to claim 1, including means associatedwith said housing for selectively and alternatively heating and coolingportions of said housing.
 8. A combined mixer, kneader and presseraccording to claim 1, including a feed line connected into said inlet, adosing lock connected to said feed line through which the material ispassed including a rotatable vane element therein, and means forrotating said vane to provide a regulated feed to said mixing portion ofsaid housing.
 9. A combined mixer, kneader and presser according toclaim 1, including a mounting base for supporting said housing, saidfixed portion of said housing being secured to said mounting base andincluding said drive means, said drive means comprising a transmissionconnected to said shaft and a motor connected to said transmission todrive said shaft.
 10. A combined mixer, kneader and presser according toclaim 1, wherein said kneading portion of said shaft comprises afrustroconical core portion with an outwardly extending progressingscrew thread which is spaced inwardly from the interior wall of saidintermediate conical kneading portion of said housing.
 11. A combinedmixer, kneader and presser according to claim 10, wherein said inlet isconnected centrally between said mixing portion and said additionalmixing portion of said housing and comprises the only feed for both ofsaid portion.
 12. A combined mixer, kneader and presser according toclaim 1, wherein there is said at least one shaft comprises a pair ofparallelly arranged laterally spaced shafts, said housing including asubstantially identical additional mixing chamber portion, intermediateportion and pressing portion arranged in parallel relationship with themixing chamber portions being interconnected centrally.
 13. A combinedmixer, kneader and presser according to claim 11, wherein said feedopening for said mixing portions for said housing is arranged centrallybetween said mixing portion and said additional mixing portion andextends substantially perpendicular to the axes thereof.
 14. A combinedmixer, kneader and presser according to claim 1, wherein said shaftpresser portion comprises a rotatable press screw and an extensionwithin a hollow portion of said kneading portion and said mixing portionof said shaft, said pressing portion of said shaft having means at theend of said extensive portion for coupling said shaft to said drivemeans.
 15. A combiNed mixer, kneader and presser according to claim 1,wherein said pressing portion of said housing comprises at least twoseparate longitudinally extending portions which are hinged together andwhich may arranged in longitudinally extending axial alignment or brokenapart and pivoted about the hinge portion to open them up.
 16. Acombined mixer, kneader and presser according to claim 1, wherein saidhousing door formation is located between said mixing portion of saidhousing and said drive means.
 17. A combined mixer, kneader and presseraccording to claim 1, wherein said housing door formation is locatedbetween said mixing portion of said housing and said intermediateportion of said housing.
 18. A combined mixer, kneader and presseraccording to claim 1, wherein said kneading portion and said mixingportion of said shaft comprise a single hollow piece, said pressingportion of said shaft comprising a press screw formation rotatable insaid housing pressing portion and an extension extending through thehollow portion of said kneading portion and said mixing portion of saidshaft and means for coupling said mixing portion and said kneadingportion and said pressing portion to said drive means.
 19. A combinedmixer, kneader and presser according to claim 18, wherein said couplingmeans comprises a squared end of said presser shaft, said drive meansincluding a recess squared end engagable with said squared end of saidpresser shaft.